Direct access storage devices (DASD) have become part of every day life, and as such, expectations and demands continually increase for better performance at lower cost. To meet these demands, the mechano-electrical assembly in a DASD device, specifically the Hard Disk Drive (HDD) has evolved to meet these demands.
An HDD is comprised of many complex parts and sub-assemblies. Each of these sub-assemblies has a manufacturing process that is required to produce a sub-assembly that functions as specified and produce these sub-assemblies in a minimal amount of time. Marginally performing sub-assemblies when coupled with other sub-assemblies can lead to marginal performance of the HDD and possibly failure of the entire HDD. Rejects and failures of sub-assemblies and longer than necessary manufacturing time equate to added cost to the final HDD.